>>turtle+QG1
Oh, I'm surprised the "blacklist" isn't just the standard English dictionary. I'm sure I'm just being naive though. Why not just blacklist any word that already exists in English?
>>tombh+IS1
There are some subtleties (e.g. hyphens, derived forms, bigrams, etc.) but the biggest problem is that most English dictionaries don't have entries for every scientific word / piece of internet slang. I ended up tokenizing Wikipedia for a blacklist and still missed a lot :(